1. Field of the Invention
The present invention relates to a console switch, and also relates to a system, a path connecting method, and a path connecting program each using the console switch.
2. Description of the Related Art
Conventionally, there have been devices such as terminal servers, console servers, and console switches. Such devices as terminal servers, console servers, and console switches, execute connection application such as Telnet, and mediate connections among the application, other devices, and selected serial ports.
Japanese Laid-Open Patent Publication No. 5-298224 (hereinafter referred to as “Patent Document 1”) discloses a console switch having the above functions. This console switch disclosed in Patent Document 1 selects one of the servers in the network, and designates the selected server as an access server. Serial ports are then connected to the access server. A remote access terminal selects servers connected to the serial ports, and connects to the selected servers, so that debugging and program reloading can be performed for the selected servers by remote control. Thus, a remote console can access two or more server consoles through a connection to a single server.
Japanese Laid-Open Patent Publication No. 2000-112851 (hereinafter referred to as “Patent Document 2”) discloses another conventional technique. In a system disclosed in Patent Document 2, when a request for address allocation is received from a terminal, a DNS (Domain Name System) server is notified of a DHCP (Dynamic Host Configuration Protocol) server, an IP (Internet Protocol) address, and the MAC (Media Access Control) address corresponding to the IP address. The DNS server sets the matching information of the host name of the terminal corresponding to the MAC address and the IP address in a DNS table. If there is an inquiry about the IP address of the terminal later, The IP address corresponding to the host name of the terminal is extracted from the DNS table and sent to the inquirer. In this manner, the DHCP server and the DNS server cooperates with each other, and the address resource is efficiently used by virtue of dynamic IP address allocation with DHCP. Also, accesses can be made among terminals with host names using DNS.
As another example of the prior art, a console switch shown in FIG. 1 has been developed. FIG. 1 illustrates a system structure using the conventional console switch. As shown in FIG. 1, a system 700 includes terminals 701 and 702, a maintenance LAN 703, a backbone LAN 704, console switches 710 through 71n, and servers S0001 through Sxx16. There are two types of LAN in the system 700; one is the maintenance LAN 703, and the other is the backbone LAN 704. The terminals 701 and 702 in which Telnet is to be executed are connected to the console switches 710 through 71n through the maintenance LAN 703.
The servers S0001 through Sxx16 connected to the console switches 710 through 71n are all connected to the backbone LAN 704, and accordingly, are separated from the maintenance LAN 703. Since the backbone LAN 704 and the maintenance LAN 703 are separated from each other, even if there is a problem caused in the backbone LAN 704, connections can be established with the serial ports of the servers S0001 through Sxx16 through the console switches 710 through 71n connected to the maintenance LAN 703. While the connections are being maintained, the cause of the problem in the backbone LAN 704 can be investigated.
The servers S0001 through Sxx16 are equipped with serial ports that are to be connected to the corresponding serial ports of the console switches 710 through 71n. The console switches 710 through 71n are connected to the maintenance LAN 703, and the terminals 701 and 702 are also connected to the maintenance LAN 703. The terminals 701 and 702 are connected to the console switches 710 through 71n via the maintenance LAN 703 using an interface such as a Telnet interface.
Here, a connecting operation to be performed to connect the terminal 701 to a serial port via the console switch 711 will be described. In this operation, the terminal 701 connects to the console switch 711 using Telnet, and switches connection destinations. In FIG. 1, the terminal 701 is to connect to the server S0018, named “apollo”, which is connected to the serial port No. 2 of the console switch 711 that has the IP address “192.168.0.15”.
In this operation, the terminal 701 that executes Telnet first needs to connect to the console switch 711. FIG. 2 shows a screen for making an access using Telnet. As can be seen from FIG. 2, the terminal 701 is a personal computer in which Microsoft Windows (a registered trademark) XP operates, and Telnet is executed in accordance with a Telnet program that is included in the default setting of Windows XP.
In FIG. 2, the terminal 701 is to connect to the console switch 711 having the IP address “192.168.0.15” through Telnet. When the enter key is pressed after the IP address is inputted as shown in FIG. 2, the terminal 701 is connected to the console switch 711 through Telnet, and has a login screen that indicates the login with the console switch 711, as shown in FIG. 3.
If a login can be carried out with “testname”, for example, the screen switches to a connecting screen shown in FIG. 4, after the input of “testname” as shown in FIG. 3. At the stage shown in FIG. 4, the terminal 701 completes the connection to the console switch 711 having the IP address “192.168.0.15”. The operation of connecting to the serial port No. 2 of the console switch 711 is then performed. So as to connect to a serial port of the console switch 711, an “open” command is executed in Telnet, so that the operation of connecting to the serial port No. 2 is started, as shown in FIG. 5. Once the connection to the port No. 2 is started, the screen shown in FIG. 5 switches to the screen shown in FIG. 6.
FIG. 6 shows the screen displaying data outputted from the serial console interface of the server S0018 that is connected to the port No. 2 of the console switch 711. When the connection is completed, the terminal 701 can operate as if connected directly to the serial port of the server S0018, though the terminal 701 is only indirectly connected to the serial port of the server S0018 via the console switch 711.
So as to switch to another server afterward, the screen switches to the screen shown in FIG. 7, so that the connection to the server S0018 is cut off. The procedures shown in FIG. 7 are carried out to cut off the connection to the port No. 2, and the terminal 701 returns to the state of being only connected to the console switch 711. When four characters “e, x, i, t” contained in an input stream are received from the terminal 701, the Telnet screen showing the connection to the serial port is ended, and returns to the screen showing that the terminal 701 has simply logged in with the console switch 711. This screen is the same as the screen shown in FIG. 4, and accordingly, the terminal 701 can connect to another server. The terminal 701 then shows a connecting screen shown in FIG. 8. To switch connections from the console switch 711 to another console switch, the procedures shown in FIGS. 4 through 8 needs to be repeated.
In a data center or the like, a large number of IP addresses and an even larger number of serial ports need to be managed in a connection list, because there are a plural number of console switches 710 through 71n. The list is searched for the name or the number of a desired server, and the serial port number and the IP address of the corresponding one of the console switches 710 through 71n are obtained. A connection to Telnet then needs to be carried out. In these procedures, it is difficult to grasp all the connection relationships. Therefore, it is very difficult to connect the terminals 701 and 702 to desired servers.
Also, the number of servers S0001 through Sxx16 that can be connected to each one of the console switches 710 through 71n is 16, 48, or the like, because the number of serial ports of the console switches 710 through 71n is much smaller than the number of servers S0001 through Sxx16, which is thousands. Therefore, it is necessary to prepare a plural number of console switches 710 through 71n for the thousands of servers S0001 through Sxx16. When the terminal 701 is to be sequentially connected to the servers S0001 through Sxx16 connected to different console switches 710 through 71n, the switching operation of executing the series of commands shown in FIGS. 2 through 8 is repeated.
In the system 700, every time connections are switched between two servers among the thousands of servers S0001 through Sxx16, the connection relationship needs to be checked, and the operations such as inputting of the IP address or the serial port number have to be performed at the time of execution of a command. This causes a problem that console switching cannot be performed frequently.
There are two types of IP address; one is IPv4, and the other is IPv6. An IPv4 address is a 32-bit address, and can be a decimal number of up to 15 digits, including periods. An IPv6 address is an address of up to 128 bits, and can be a hexadecimal number of 19 digits, including colons. Having more digits than a decimal number, a hexadecimal number requires more input characters. Therefore, an IPv4 address can be inputted through ten keys, while an IPv6 address with alphabets cannot be inputted swiftly. When the corresponding IP address is to be extracted from the list, the large number of digits and character types adds load to the checking process. This causes a problem that a terminal cannot be easily connected to a desired server.